After the bare cell of a secondary lithium battery is covered up and down by two outer packages, there will exist a quite thin layer of aluminum on the covered interface, which will result in a risk of short circuit of the electrical component if the aluminum layer is exposed, and the edge sealing process is to cover the aluminum layer with an adhesive tape or glue, so as to prevent exposure of aluminum. While the conventional single edge folding and double edge folding are both applied to the rectangular battery with a regular shape.
The single edge folding process refers to that the glue is sprayed on the section from which aluminum is exposed by a spray gun controlling the amount of glue sprayed, then a single time of edge folding is performed. Or firstly performing edge folding and then sealing the section from which aluminum is exposed after the edge folding with an adhesive tape. The double edge folding process refers to that two times of edge folding are performed to cover the section from which aluminum is exposed in the area of the second time of edge folding, so as to achieve the objective of edge sealing. However, the existing single edge folding process and the double edge folding process are both limited to the rectangular battery with a regular shape, the device only needs to position the cell, coat glue and fold the edge. When the battery is an irregular or complex structure, the device will be unable to move along the edge of the outer package in a straight line due to the design problem, and the glue or adhesive tape will be unable to completely cover the section, which may cause the risk of exposing aluminum. Therefore, the conventional solution cannot be applied to the battery cell with an irregular shape. In view of the above, the present application is provided.